So you got a full-size freezer or deep-freeze, but you don't use all the space. Whether you rent or may need the space later you don't have to pay for that wasted space. So I'm going to teach you NEUTRAL LOADING. The simple idea of loading insulating material to avoid paying to cool or heat air.
Step 1: Materials.
1.Several plastic grocery bags.
Who said 2 wrongs don't make a right? Rather than throwing out those evil plastic bags and non-biodegradable styrofoam peanuts you can reuse them to save energy.
Simply fill one plastic sack with peanuts and then use another bag to cover the gap making a Styrofoam pillow. You can double-bag or use plastic bags as filler also. Seal the ends with clear packaging tape and your done. Make enough pillows to fill the unused space in your freezer or deep-freeze.